asked 63.9k views
4 votes
The sum of the digits of a two digit number is 7, and their product is 10. What is the number?

100pts

2 Answers

3 votes

25 because


2 + 5 = 7


2 * 5 = 10

answered
User Daniel Barde
by
8.7k points
3 votes

Answer:The numbers are 5 and 2

Explanation:

Let x represent the first digit number.

Let y represent the second digit number.

The sum of the digits of a two digit number is 7. This means that

x + y = 7 - - - - - - - - - - - -1

The product of the digits is 10. This means that

xy = 10 - - - - - - - - - - - -2

Substituting x = 7 - y into equation 2, it becomes

y(7 - y) = 10

7y - y^2 = 10

y^2 - 7y + 10 = 0

y^2 - 5y - 2y + 10 = 0

y(y - 5) - 2(y - 5) = 0

y - 2 = 0 or y - 5 = 0

y = 2 or y = 5

Substituting y = 2 or y = 5 into

x = 7 - y, it becomes

x = 7 - 2 = 5 or x = 7 - 5 = 2

The numbers are 5 and 2

answered
User Jacxel
by
7.6k points
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